1. Field of the Invention
This invention relates to a method and apparatus for setting in place within an instant-release type molding machine for a concrete product a pattern frame for molding a product and a press die for compression molding concrete material fed in the cavity of the pattern frame.
2. Description of the Prior Art
In the instant-release type concrete molding machine, the steps of filling a pattern frame with stiff concrete, molding the concrete, and immediately releasing the molded concrete product from the pattern frame are repeated. Unlike the cast concrete molding machine, this instant-release type molding machine enjoys the advantage that it does not require any provision for alternately removing a pattern frame filled with stiff concrete and inserting an empty pattern frame. The instant-release type molding machine by nature entails the necessity for changing pattern frames whenever a prescribed number of concrete products have been molded in a pattern frame of a given shape and other concrete products are to be molded in a pattern frame of a different shape. This change of pattern frames has heretofore been effected manually with the aid of a crane. Especially, the bolts and nuts for fixing many shock-absorbing members in place within the machine have been fastened and unfastened manually. This work is complicated and consumes much time. The operation of the molding machine has to be suspended while this work is in progress. This fact has significantly impaired the productivity of the instant-release type molding machine.